This application relates to a unique method and apparatus for returning the oil to a sump in a sealed compressor.
Sealed compressors are utilized in many refrigerant compression applications. In a typical sealed compressor, a pump unit is incorporated within a hermetically sealed housing. A refrigerant is introduced into the housing in a suction chamber through a suction tube. Typically, an electric motor drives a shaft which powers the pump unit. This refrigerant passes over the electric motor, cooling the motor. The refrigerant then passes into the pump unit, is compressed, and is passed to a discharge chamber. The suction and discharge chamber are separated by appropriate structure.
In one popular type of compressor pump unit, the compressor pump unit comprises a pair of scroll members. A scroll compressor includes two opposed scroll members each having a base and a generally spiral wrap extending from the base. One of the two scroll members is caused to be driven to orbit relative to the other. The wraps interfit, and as the wraps orbit, compression chambers defined between the wraps are reduced in volume.
Typically, sealed compressor housings have been a relatively long length. The suction tube has generally entered the chamber at a location aligned with the pump unit, or at least between the pump unit and the top end of the motor stator windings.
More recently, it has become desirable to reduce the height of sealed compressors, and in particular scroll compressors. However, certain problems become introduced with the reduced height sealed compressor. In one example, oil must be returned from the pump unit to a sump in the compressor. The oil will typically fall from the pump unit downwardly to the sump. However, it is also desirable to ensure that the oil is isolated from suction gas turbulence, as this could cause undesirable entrainment of the oil into the refrigerant entering the chamber.
This problem becomes particularly acute when the height is reduced, as it becomes more difficult to ensure that the returned oil does not pass in front of the suction tube.
In a disclosed embodiment of this invention, a sealed compressor incorporates a suction tube which is at least partially aligned with the windings on the motor stator for driving a compressor pump unit. An oil return tube returns oil from the compressor pump unit through a tube, and confines the oil return to a circumferential extent which does not include the suction tube. That is, the oil return tube ensures that the oil does not pass in front of the suction gas entering the compression chamber. Stated another way, the oil return structure prevents the returned oil from mixing with the suction gas.
In a preferred embodiment, the oil return tube is at a location generally opposed by 155xc2x0 from the suction tube.
These and other features of the present invention can be best understood from the following specifications and drawings, the following of which is a brief description.